Polyacetals containing acetaldehyde acetal units, preparation thereof and use thereof in detergents and cleaners

ABSTRACT

Soluble polyacetals containing acetaldehyde acetal units are obtainable by cationically initiated addition polymerization of 
     (a) compounds containing at least 3 hydroxyl groups, and 
     (b) divinyl ethers containing terminal vinyl ether groups, or mixtures of such divinyl ethers and monovinyl ethers, in the presence or absence of 
     (c) dihydroxy compounds and/or monohydroxy compounds, and are useful as admixture in phosphate-reduced and phosphate-free detergents and cleaners and as dispersant for finely divided minerals.

This application is a 371 of PCT/EP 93/02613 filed Sep. 25, 1993.

The present invention relates to soluble polyacetals which containacetaldehyde acetal units and which are obtainable by cationicallyinitiated polyaddition of alcohols and divinyl ethers, to a process forpreparing said acetals, and to the use of the acetals in detergents andcleaners and as dispersants for finely divided minerals.

Journal of Polymer Science: Polymer Letters Edition 18 (1980), 293-297discloses the preparation of polyacetals by acid-catalyzed addition ofpolyols to divinyl ethers. For instance, polyaddition oftrans-1,4-cyclohexanedimethanol to butanediol divinyl ether under thecatalytic effect of p-toluenesulfonic acid produces a polyacetal havinga molecular weight of 200,000.

The reaction of diethylene glycol divinyl ether, bisphenol A and1,1,1-trimethylolpropane in a molar ratio of 6:3:2 in the presence oftrichloroacetic acid as catalyst produces crosslinked polyacetals. Thepolyacetals are used in medicine for the controlled release of activecompounds.

FR-A-2 336 936 likewise discloses the preparation of crosslinkedinsoluble polyacetals. The crosslinked polyacetals are obtained byreaction of cyclic divinyl ethers with glycerol.

It is an object of the present invention to provide novel solublesubstances based on polyols and divinyl ethers and a process forpreparing the novel substances. It is a further object to describedetergent and cleaner additives which reduce the viscosity of nonionicsurfactants.

We have found that these objects are achieved according to the inventionby soluble polyacetals containing acetaldehyde acetal units, obtainableby cationically initiated polyaddition of

(a) compounds containing at least 3 hydroxyl groups,

(b) divinyl ethers containing terminal vinyl ether groups, or mixturesof such divinyl ethers and monovinyl ethers, and

(c) dihydroxy compounds and/or monohydroxy compounds, the sum of thehydroxyl groups of the compounds (a) and (c) relative to the sum of thevinyl ether groups of compounds (b) being from 0.1 to 10.

The invention further provides a process for preparing water-solublepolyacetals containing acetaldehyde acetal units, which comprisesreacting

(a) compounds containing at least 3 hydroxyl groups,

(b) divinyl ethers containing terminal vinyl ether groups, or mixturesof such divinyl ethers and monovinyl ethers,

and

(c) dihydroxy compounds and/or monohydroxy compounds and

acid catalysts which initiate the cationic polyaddition at temperaturesof from -20° to 250° C. in such ratios that the sum of the hydroxylgroups of the compounds (a) and (c) relative to the sum of the vinylether groups of compounds (b) being from 0.1 to 10. The solublepolyacetals are used as admixture in phosphate-reduced andphosphate-free detergents and cleaners and also as dispersant for finelydivided minerals.

The reaction of the components (a) and (b) can be made to proceedwithout crosslinking--even in the absence of dihydroxy compounds and/ormonohydroxy compounds--by ensuring that the ratio of the hydroxyl groupsto vinyl ether groups in the compounds (a) and (b) is greater thanunity. The crosslinking of the resulting polyacetals can also beeffectively prevented by using compounds of group (c) in thepolyaddition. These compounds are used in the polyaddition in suchamounts that water-soluble polyacetals containing acetaldehyde acetalunits are formed.

Suitable compounds of group (a), polyhydroxy compounds which contain atleast 3 OH groups in the molecule, include for example glycerol,oligoglycerols having from 2 to 10 glycerol units, trimethylolpropane,erythritol, pentaerythritol, polyvinyl alcohols having molecular weightsup to 100,000, polyallyl alcohols having molecular weights (numberaverage) up to 100,000, polyhydroxymethylenes obtainable bypolymerization of vinylidene carbonate, monosaccharides such as glucose,mannose, fructose, levoglucosan, disaccharides such as sucrose, lactose,maltose, leucrose, isomaltose, isomaltulose, oligo- and polysaccharidessuch as degraded starch, starch, inulin, fructopolysaccharides,maltodextrins, pentoses, levan, branched fructans, reduced carbohydratessuch as sorbitol, mannitol, isomalt, inositol and oxidized carbohydrateswhich carry carboxyl groups, such as sugarcarboxylic acids, gluconicacid and mucic acid and also modified carbohydrates, such as C₁ -C₂₀-alkylglucosides, such as methylglucoside, ethylglucoside,n-propylglucoside, isopropylglucoside, n-butylglucoside,isobutylglucoside, n-hexylglucoside and palmitylglucoside andlevoglucan. Preferred compounds of group (a) are glucose, sucrose,alkylglucosides such as methylglucoside, dextrose, sorbitol, mannitol,erythritol and pentaerythritol.

The compounds of group (b) are divinyl ethers which contain terminalvinyl ether groups, or mixtures thereof with monovinyl ethers. Suitabledivinyl ethers include for example all doubly vinylated diols, e.g.ethylene glycol divinyl ether, propylene glycol divinyl ether,butanediol divinyl ether, butynediol divinyl ether, butenediol divinylether, hexanediol divinyl ether, bis(hyroxymethyl)cyclohexane divinylether, diethylene glycol divinyl ether, triethylene glycol divinylether, tetraethylene glycol divinyl ether and also divinyl ethers ofpolyethylene glycols where the polyethylene glycol has a molecularweight of up to 20,000, polypropylene glycol divinyl ethers havingmolecular weights of up to 10,000 and also divinyl ethers of copolymersof polyethylene oxide and polypropylene oxide having molecular weightsof up to 10,000 and also polytetrahydrofuran divinyl ether. Preferredcompounds of group (b) are 1,4-butanediol divinyl ether, 1,6-hexanedioldivinyl ether, ethylene glycol divinyl ether, diethylene glycol divinylether and triethylene glycol divinyl ether.

Suitable monovinyl ethers for use in mixture with the divinyl ethersinclude for example C₁ -C₂₀ -alkyl vinyl ethers, such as methyl vinylether, ethyl vinyl ether, n-propyl vinyl ether, isopropyl vinyl ether,n-butyl vinyl ether, isobutyl vinyl ether, hexyl vinyl ether,2-ethylhexyl vinyl ether, octyl vinyl ether, decyl vinyl ether and C₂₀-alkyl vinyl ether. Other suitable monovinyl ethers include phenyl vinylether, vinyl ethers of hydroxycarboxylic esters, such as ethylvinyloxyacetate, methyl vinyloxyacetate, ethyl vinyloxypropionate,methyl vinyloxypropionate, methyl vinyloxyvalerate, ethylvinyloxyvalerate, dimethyl vinyloxysuccinate, methyl vinyloxystearate,trimethyl vinyloxytricarballylate, vinyl ethers of trialkyl citrates,such as the vinyl ether of trimethyl citrate and the vinyl ether oftriethyl citrate. The monovinyl ethers used can also be glucals, e.g.triacetylgalactalglucal or tetrabenzyl-2-hydroxyglucal.

Further suitable monovinyl ethers are hydroxyvinyl ethers obtainable forexample by vinylation of a hydroxyl group of diols. Suitable monovinylethers of this kind include for example butanediol monovinyl ether,hexanediol monovinyl ether, diethylene glycol monovinyl ether,triethylene glycol monovinyl ether, tetraethylene glycol monovinylether, pentaethylene glycol monovinyl ether and also monovinyl ethers ofcopolymers of ethylene oxide and propylene oxide and monovinyl ethers ofpolyethylene oxide and propylene oxide having molecular weights (numberaverage) of up to 10,000.

A component (b) mixture of divinyl ethers and monovinyl ethers containsfrom 1 to 100, preferably from 20 to 100, mol % of divinyl etherscontaining terminal vinyl ether groups.

The monomers of group (c) are dihydroxy compounds and/or monohydroxycompounds. Usable dihydroxy compounds include in principle all compoundswhich have 2 OH groups, for example alkylene glycols, such as ethyleneglycol, diethylene glycol, triethylene glycol, tetraethylene glycol,polyethylene glycols up to molecular weights of 10,000, propyleneglycol, dipropylene glycol, polypropylene glycols with molecular weightsof up to 10,000, copolymers of ethylene oxide and propylene oxide andoptionally butylene oxide with molecular weights of up to 10,000,polytetrahydrofuran with molecular weights of up to 10,000,1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,2-pentanediol,neopentylglycol, 1,5-pentanediol, 1,2-hexanediol, 1,3-hexanediol,1,4-hexanediol, 1,5-hexanediol, 1,6-hexanediol, 1,7-heptanediol,1,8-octanediol, 2,5-dimethyl-2,5-hexanediol,1,4-bis-(hydroxymethyl)cyclohexane, pyrocatechol, resorcinol andhydroquinone. In addition to alkylene glycols and phenols it is alsopossible to use those dihydroxy compounds as monomers of group (c) whichadditionally carry further functional groups, for example ester, amide,nitrile, ether, acetal, imidoester, ketone, imide and thioether groupsand also CC double or triple bonds. Examples of suitable compounds ofthis kind are dimethyl tartrate, diethyl tartrate, methyl2,2-bis(hydroxymethyl)propionate, 3-hydroxy-2,2-dimethylpropylhydroxypivalate, 2-butene-1,4-diol and 3-hexyne-2,5-diol,bis(2-hydroxyethyl) terephthalate, 1-phenylethylene glycol, andoctadecanediol from hydrogenated castor oil. Examples of furthersuitable monomers of group (c) are dihydroxycarboxylic esters which canbe isolated from natural fats and oils or are preparable by enzymatic,bacterial or chemical reactions. Examples of such compounds aredihydroxy fatty acids such as 10,12-dihydroxystearic acid,9,10-dihydroxystearic acid, 9,12-dihydroxy-10-octadecenoic acid,9,12-dihydroxy-9-oxo-10-octadecenoic acid,10,13-dihydroxy-11-octadecenoic acid and12,13-dihydroxy-9-oxo-10-octadecenoic acid. Dihydroxy fatty esters arealso obtainable by hydroxylating and oxidizing fatty acids of naturalorigin, for example from ricinoleic acid, linoleic acid, oleic acid,linolenic acid, elaidic acid, palmitoleic acid, myristoleic acid,palmitic acid and stearic acid. Diols formed by elimination of waterfrom polyols, for example dianhydrosorbitol, dianhydromannitol anddianhydroerythritol, are likewise suitable. Preferred monomers of group(c) are triethylene glycol, dimethyl tartrate and diethyl tartrate.

Suitable monohydroxy compounds of group (c), which are optionallyincludable in the cationically initiated polyaddition, are aliphatic andaromatic compounds which each have one hydroxyl group. The customarilyenvisioned hydroxyl-containing aliphatic and aromatic compounds have upto 30 carbon atoms in the molecule. These compounds are primarilyalcohols and phenols. However, they may additionally contain furtherfunctional groups, for example ester, amide, nitrile, ether, acetal,amidoester, imide and thioether groups and also CC double or triplebonds. Examples of suitable compounds are monohydric C₁ -C₃₀ -alcohols,such as methanol, ethanol, n-propanol, isopropanol, n-butanol,isobutanol, tert-butanol, pentanols, 2-methylbutanol, 3-methylbutanol,tert-amyl alcohol, 3-methyl-3-pentanol, cyclohexanol, n-hexanol,n-octanol, isooctanol, decanol, dodecanol, stearyl alcohol and palmitylalcohol, and also oxo alcohols which are obtainable by addition ofcarbon monoxide and hydrogen to olefins by the oxo process, allylalcohol, phenol, o-, m- and p-cresol, alkylphenols, benzyl alcohol,propargyl alcohol, butynol, 3-methyl-3-buten-1-ol,3-methyl-2-buten-1-ol, 2-methyl-3-buten-2-ol, 2-methyl-3-butyn-2-ol and1-ethynylcyclohexanol.

Further possible monomers of group (c) are reaction products ofmonohydric alcohols and phenols with from 1 to 100 mol of alkyleneoxides. Suitable alkylene oxides are for example ethylene oxide,propylene oxide and butylene oxides. Suitable alkoxylation products arefor example ethylene glycol monomethyl ether, ethylene glycol monoethylether, ethylene glycol monobutyl ether, propylene glycol monobutylether, 1,2-butylene glycol monomethyl ether, 2-(4-methoxyphenyl)ethanol,diethylene glycol monomethyl ether, diethylene glycol monoethyl ether,diethylene glycol monobutyl ether, reaction products of 1 mol ofmethanol with 3.9 or 25 mol of ethylene oxide, reaction products of anoxo alcohol with from 3 to 25 mol of ethylene oxide. Further suitablemonofunctional alcohols are for example ethylenechlorohydrin,propylenechlorohydrin, 6-chlorohexanol, 8-chlorooctanol, methylglycolate, ethyl glycolate, methyl lactate, ethyl lactate, isopropyllactate, n-butyl lactate, isobutyl lactate, methyl mandelate, ethylmandelate, hydroxypropionitrile, methyl hydroxybutyrate, ethylhydroxybutyrate, methyl hydroxyvalerate, ethyl hydroxyvalerate,isopropyl hydroxyvalerate, methyl hydroxyisovalerate, ethylhydroxyisovalerate, methyl hydroxyisobutyrate, ethyl hydroxyisobutyrate,methyl hydroxypivalate, ethyl hydroxypivalate, ethyl benzylate,mandelonitrile, diethyl hydroxymalonate, diethyl hydroxymethylmaleate,diethyl hydroxymethylmalonate, diethyl malate, triethyl citrate, ethylhydroxycrotonate, dimethyl malate, trimethyl citrate, tri-n-propylcitrate, methyl hydroxycrotonate, methyl 3-hydroxy-4-hexenoate,2-hydroxy-3,3-dimethylbutyrolactone, hydroxyacetone, glycolaldehyde,vanillin, eugenol, salicylaldehyde and acetoin.

It is also possible to use hydroxy fatty esters preparable bacterially,enzymatically or by chemical hydroxylation of oils or fats of naturalorigin, for example on the basis of linoleic acid, linolenic acid, oleicacid, elaidic acid, ricinoleic acid, palmitic acid and stearic acid.This produces for example methyl 10-hydroxy-12-octadecenoate, methyl10-hydroxy-12,15-octadecadienoate, methyl 12-hydroxyoleate, methylricinoleate, methyl 10-hydroxyoctadecanoate, methyl 10-hydroxystearate,methyl hydroxypalmitate, methyl 10-hydroxyhexadecanoate, methyl13-hydroxy-12,13-epoxy-10-octadecanoate, methyl9-hydroxy-10-oxo-12-octadecenoate and methyl 13-hydroxypalmitate.

All monomers of group (c) can be used in the form of the mono-anddivinyl ethers as monomers of group (b).

The monomers (a), (b) and (c) are polymerized cationically. Thisinvolves the addition of the OH group of a monomer of group (a) to avinyl ether group of the monomer of group (b) to form an acetaldehydeacetal. This polymerization results in a polymeric main or side chain inwhich the monomer units are held together by acetaldehyde acetal unitsof the structure ##STR1##

The ratio of the sum of the hydroxyl groups of compounds (a) and (c) tothe sum of the vinyl ether groups of compounds (b) is customarily from0.1:1 to 10:1, preferably from 0.5:1 to 5:1.

The cationic copolymerization of the monomers of groups (a), (b) andoptionally (c) can be initiated with the aid of any organic or inorganicacidic substance. Suitable cationic initiators are for example oxalicacid, tartaric acid, adipic acid, succinic acid, succinic anhydride,citric acid, formic acid, acetic acid, propionic acid, malic acid,monohalogenated or polyhalogenated carboxylic acids, such astrifluoroacetic acid or trichloroacetic acid, hydrogen chloride,hydrogen bromide, hydrogen iodide, sulfuric acid, phosphoric acid,benzenesulfonic acid, p-toluenesulfonic acid, boric acid, ascorbic acid,acidic alumina, aluminum sulfate, potassium aluminum sulfate, iron(II)sulfate, iron(III) sulfate, aluminum oxide, titanium sulfate, iron(III)chloride, boron trifluoride, boron trichloride, boron tribromide,iodine, ion exchangers in the acid form, and acid-loaded inert solidsubstances. The initiators for the cationic polymerization arecustomarily used in amounts of from 0.001 to 20, preferably from 0.01 to1, % by weight, based on the monomers of groups (a) and (b). Thecopolymerization is generally highly exothermic. Depending on theactivity of the initiator used, the reaction temperatures range from-20° to 250° C., preferably from 0° to 200° C.

Soluble polyacetals containing acetaldehyde acetal units are obtainablefor example by reacting the following compounds:

starch, butanediol divinyl ether, ethyl lactate,

starch, triethylene glycol divinyl ether and ethyl vinyloxyacetate,

starch, butanediol divinyl ether, triethylene glycol and ethyl lactate,

starch, butanediol divinyl ether and citric acid,

starch, butanediol divinyl ether and triethyl citrate,

degraded starch, butanediol divinyl ether and ethyl vinyloxypropionate,

degraded starch, butanediol divinyl ether, ethyl glycolate,

degraded starch, butynediol divinyl ether and ethyl vinyloxyacetate,

degraded starch, butenediol divinyl ether and hydroxybutyl vinyl etherethoxylates,

dextrin, hydroxybutyl vinyl ether ethoxylates, triethylene glycoldivinyl ether and ethyl vinyloxyacetate,

dextrin, diethyl tartrate, ethyl lactate and butanediol divinyl ether,

sucrose, butanediol divinyl ether and ethyl vinyloxyacetate,

sucrose, butanediol divinyl ether and ethyl lactate,

sucrose, triethylene glycol, butanediol divinyl ether and ethyl lactate,

sucrose, diethyl tartrate, butynediol divinyl ether and ethyl lactate,

sucrose, diethyl tartrate, butanediol divinyl ether and triethylcitrate,

sucrose, diethyl tartrate, butanediol divinyl ether and citric acid,

lactose, diethyl tartrate, butanediol divinyl ether and ethyl lactate,

lactose, ethyl vinyloxyacetate and butanediol divinyl ether,

glucose, diethyl tartrate, butanediol divinyl ether and ethyl lactate,

glucose, triethylene glycol, butanediol divinyl ether and ethyl lactate,

glucose, ethyl vinyloxyacetate and butanediol divinyl ether,

sorbitol, ethyl vinyloxyacetate and butanediol divinyl ether,

sorbitol, triethylene glycol, butanediol divinyl ether and ethyllactate,

sorbitol, diethyl tartrate, butanediol divinyl ether and ethylglycolate,

sorbitol, octadecyl vinyl ether and butanediol divinyl ether,

sorbitol, butanediol divinyl ether, ethyl vinyloxyacetate and octadecylvinyl ether,

methylglucoside, ethyl vinyloxyacetate, butanediol divinyl ether andoctadecyl vinyl ether,

methylglucoside, diethyl tartrate, butanediol divinyl ether and ethylglycolate,

methylglucoside, triethylene glycol, butanediol divinyl ether and ethyllactate,

methylglycoside, tartaric acid, butanediol divinyl ether and citricacid.

The process for preparing soluble polyacetals which contain acetaldehydeacetal units which are virtually not crosslinked comprises reacting

(a) compounds containing at least 3 hydroxyl groups, and

(b) divinyl ethers containing terminal vinyl ether groups, or mixturesof such divinyl ethers and alkyl vinyl ethers, in the presence of

(c) dihydroxy compounds and/or monohydroxy compounds and acid catalystswhich initiate the cationic polyaddition

at temperatures of at least -20° C. in such ratios that water-solubleaddition products are produced. The order in which the components areadded to the reaction mixture is optional. Preference is given toinitially charging the compounds of component (a) together with theinitiator and adding the other reaction components in succession. Forinstance, 1 mol of sorbitol can be reacted first with 1 mol of ethylvinyloxyacetate, then with 1 mol of octadecyl vinyl ether and thereafterwith 1 mol of butanediol divinyl ether. However, it is also possiblefirst to react for example 1 mol of sorbitol together with 4 mol ofethyl vinyloxyacetate and thereafter with 1 mol of butanediol divinylether. Another example of the preparation of the polyacetals comprisesreacting a solution of methylglucoside and triethylene glycol withbutanediol divinyl ether. Similarly, polyacetals are produced onreacting a solution of methylglucoside in diethyl tartrate withbutanediol divinyl ether.

However, it is also possible to react a suspension of methylglucoside indiethyl tartrate or triethylene glycol with butanediol divinyl ether orto cationically polymerize methylglucoside first with ethylvinyloxyacetate and thereafter with butanediol divinyl ether.

Similarly, solids such as starch can be included in this reaction byreacting for example starch first with ethyl vinyloxyacetate and thenwith butanediol divinyl ether. The reaction product can additionally bereacted with triethyl citrate, in which case this ester adds to a vinylether group still present in the polyacetal. Starch can also be reactedinitially with butanediol divinyl ether and then with triethyl citrateor with trimethyl citrate to form polyacetals containing acetaldehydeacetal units. The reverse order is also possible by first reactingbutanediol divinyl ether with triethyl or trimethyl citrate and then toreact the reaction product with starch. Instead of starch it is alsopossible to use methylglucoside.

The compounds of group (a) are at least at higher temperatures solublein the dihydroxy compounds of component (c). It thus depends on thetemperature whether a solution or a suspension of the compound of group(a) in the dihydroxy compounds and/or monohydroxy compounds used in thereaction. For example, methylglucoside forms a completely clear solutionin diethyl tartrate at 150° C., whereas at below 150° C. it dissolvesonly incompletely and thus forms a suspension or saturated solution. Thesolution or suspension is subsequently admixed and reacted with at leastone compound of group (b), for example with butanediol divinyl ether.

The preparation of the soluble/uncrosslinked polyacetals requires noinert solvents. On the contrary, the compounds of group (c) can be usedas diluents. Preference is given to starting from a melt, a slurry or asolution of the compounds (a) in a compound of group (c) and conductingthe cationically initiated polyaddition at temperatures of at least 70°C., preferably at temperatures of above 90° C., by adding the compoundsof group (b) a little at a time or continuously in the presence ofcationic catalysts. The catalysts can be introduced into the reactionzone for example together with the compounds of group (c). However, itis also possible to admix the compounds which contain at least 3hydroxyl groups (i.e. the compounds of group (a)) with the totalrequired amount of compounds of group (b) and catalyst and heat themixture to the reaction temperature required. The compounds of group (a)and the compound of group (b) are frequently not miscible with oneanother. As mentioned above, however, the cationically initiatedaddition reaction leads to the formation of the homogeneous reactionmixture. For example, a homogeneous, clear and colorless reactionmixture is obtained on reacting methylglucoside or sorbitol with ethylvinyloxyacetate and 1,4-butanediol divinyl ether in the presence ofcatalytic amounts of oxalic acid. In this case the reaction temperaturespreferably range from 110° to 170° C. The course of the additionreaction can be monitored by iodometric titration of the vinyl ethergroups.

The polyacetal containing acetaldehyde acetal units have K values(determined by the method of H. Fikentscher in tetrahydrofuran at 25° C.and at a polyacetal concentration of 1% by weight) ranging from 9 to100. They are hydrolyzable at below pH 7. Hydrolysis cleaves theacetaldehyde acetal units into acetaldehyde and other hydrolysisproducts. The hydrolysis products are biodegradable. The influence ofcarbon dioxide is enough to bring about the hydrolytic cleavage of theacetal groups in aqueous solution. The polyacetals are biodegradable.They are used as admixtures in phosphate-reduced and phosphate-freedetergent and cleaner formulations and as dispersants for finely dividedminerals, in particular clay minerals, titanium dioxide and chalk.

Phosphate-reduced detergents are those detergents whose phosphatecontent is less than 25% by weight, calculated as sodium triphosphate.The compositions of detergent and cleaner formulations can vary greatly.Detergent and cleaner formulations customarily contain from 2 to 50% byweight of surfactants with or without girders. This applies to bothliquid and pulverulent detergent and cleaner formulations. Examples ofthe compositions of detergent formulations which are customary inEurope, the U.S. and Japan may be found for example in table form inChemical and Eng. News, 67 (1989), 35, in WO-A-90/13581 and also inUllmanns Encyklopadie der technischen Chemie, Verlag Chemie, Weinheim1983, 4th edition, pages 63-160. Also of interest are those detergentformulations which contain up to 60% by weight of an alkali metalsilicate and up to 10% by weight of a polyacetal produced according tothe invention.

The detergents may additionally contain a bleaching agent, for examplesodium perborate, which, if used, can be present in the detergentformulation in amounts of up to 30% by weight. The detergent and thecleaner formulations may contain further customary admixtures, forexample complexing agents, opacifiers, optical brighteners, enzymes,perfume oils, color transfer inhibitors, grayness inhibitors and/orbleach activators and also zeolite.

The polyacetals are used in detergents in amounts from 0.5 to 20,preferably 2 to 10, % by weight.

The hydrolyzed and neutralized polyacetals are also suitable for use asdispersants for finely divided substances, for example clays, chalk,calcium carbonate, titanium dioxide, iron oxides, kaolins, aluminumoxide, cement and oxidic glazes for ceramic purposes. When used asdispersants, they are customarily required in amounts from 0.02 to 1% byweight, based on the finely divided substances.

The percentages in the Examples are by weight. The K values of thepolyacetals were determined in 1% strength solution in tetrahydrofuranat 25° C. by the method of H. Fikentscher, cf. Cell. Chem. 13 (1932),58-64, 71-74.

EXAMPLES

General method for the alkaline aftertreatment of the estergroup-carrying polyacetals (preparation of aqueous sodium saltsolutions):

To 30 g of polyacetal are added 150 ml of ethanol and the esters aresaponified by addition of equivalent amounts of a 25% strength aqueoussodium hydroxide solution. The saponification of the ester groups iseffected at a temperature of 20° C. Thereafter the ethanol is removedunder reduced pressure and the resulting solution is diluted with water.

General method for preparing the polyacetals containing acetaldehydeacetal units

A round-bottom flask equipped with a stirrer and with a device forworking under nitrogen is charged with components (a) and (c), followedby 0.3 g of oxalic acid. The mixture is then heated to a temperature of150° C. A homogeneous solution forms at temperatures above 150° C.1,4-Butanediol divinyl ether (component (b)) is metered in and thereaction mixture is allowed to afterreact at 150° C. for 1 hour. Thedecrease in the vinyl ether group content is determined by means of theiodine titration of samples of the reaction mixture. On completion ofthe polyaddition the vinyl ether group content is less than 1/100 of theinitial value. To stabilize the polyacetals, 2 g of solid sodiumbicarbonate are powdered. Table 1 indicates the starting materials, theratio of the hydroxyl groups to the vinyl ether groups in the startingmaterials, and the K values of the polyacetals obtained.

                                      TABLE 1                                     __________________________________________________________________________               Component                                                                                      (b)                                                          (a)      (c)     Butanediol                                                   Methylglucoside                                                                        Diethyl tartrate                                                                      divinyl ether                                                                        Ratio of OH/VE                                                                         K value of                        Example                                                                            Polyacetal                                                                          (g)      (g)     (g)    groups   polyacetal                        __________________________________________________________________________    1    1     39       62      92     1.26     14                                2    2     39       41      78     1.10     14                                3    3     39       .sup.  45.sup.1)                                                                      85     1.3      16                                4    4     39       41      71     1.2      11                                5    5     39       62      78     1.27      9                                6    6     39       21      57     1.25     14                                7    7     39       41      78     1.09     18                                __________________________________________________________________________     .sup.1) diethyl tartrate replaced by triethylene glycol                  

EXAMPLE 8

Polyacetal 8 is prepared according to the general method by reacting asolution of 39.5 g (0.2 mol) of glucose, 45 g (0.3 mol) of triethyleneglycol and 0.3 g of oxalic acid at 145° C. with 92 g (0.65 mol) ofbutanediol divinyl ether. The ratio of the OH groups to the vinyl ethergroups was 1.08. The K value of polyacetal 8 is 22. Alkalineaftertreatment (cf. above) gives the sodium salt solution.

EXAMPLE 9

Polyacetal 9 is prepared according to the general method by reacting asolution of 68.5 g (0.2 mol) of sucrose, 62 g (0.3 mol) of diethyltartrate and 0.3 g of oxalic acid at 110° C. with 78 g (0.55 mol) ofbutanediol divinyl ether. The K value of the polyacetal thus obtained is10. Alkaline aftertreatment as per the above-indicated method gives thesodium salt solution. In the starting materials the ratio of the OHgroups to the vinyl ether groups was 2.14.

EXAMPLE 10

Polyacetal 10 is prepared according to the above-indicated generalmethod by reacting a solution of 68.5 g (0.2 mol) of sucrose, 45 g (0.3mol) of triethylene glycol and 0.3 g of oxalic acid at 110° C. with 99 g(0.7 mol) of 1,4-butanediol divinyl ether. The ratio of the OH groups tothe vinyl ether groups is 1.57. The polyacetal obtained has a K value of11. Alkaline aftertreatment gives the sodium salt solution of thepolyacetal.

EXAMPLES 11 TO 16

The above-indicated method is followed when a solution of ethyl lactateand butanediol divinyl ether is added to a solution or suspension ofmethylglucoside in diethyl tartrate containing 0.2 g of oxalic acid. Thequantities used, the reaction temperature and the ratio of the OH groupsto the vinyl ether groups in the starting materials is indicated inTable 2 together with the K values of the polyacetals.

                                      TABLE 2                                     __________________________________________________________________________               Component                                                                              (c)         (b)                                                      (a)      Diethyl                                                                            (c)    Butanediol Ratio of                                Polyacetal                                                                          Methylglucoside                                                                        tartrate                                                                           Ethyl lactate                                                                        divinyl ether                                                                        Temp.                                                                             OH/VE                              Example                                                                            No.   (g)      (g)  (g)    (g)    (°C.)                                                                      groups                                                                             K value                       __________________________________________________________________________    11   11    39       21   3      57     155 1.28 28                            12   12    39       21   3.5    57     140 1.29 10                            13   13    39       21   6      57     150 1.31 13                            14   14    39       21   3.5    57     150 1.29 14                            15   15    39       21   3.5    57     110 1.29 11                            16   16    39       --   27.sup.a)                                                                            39     145 1.11 12                            __________________________________________________________________________     .sup.a) diethyl lactate replaced by diethylene glycol monoethyl ether    

EXAMPLES 17 TO 21

The amounts of methylglucoside and ethyl vinyloxyacetate reported inTable 3 are weighed into a round-bottom flask, admixed with from 20 to40 mg of oxalic acid and heated at 130° C. until a homogeneous mixturehas formed. Then butanediol divinyl ether is added and the reactionmixture is held at 130° C. for 1 hour. The K values of the polyacetalsthus obtainable are reported in Table 3. Alkaline aftertreatment of thepolyacetals with sodium hydroxide solution gives the sodium salts.

                                      TABLE 3                                     __________________________________________________________________________               Component                                                                              (b)     (b)                                                          (a)      Ethyl   Butanediol divinyl                                     Polyacetal                                                                          Methylglucoside                                                                        vinyloxyacetate                                                                       ether    Ratio of                                 Example                                                                            No.   (mmol)   (mmol)  (mmol)   OH/VE groups                                                                          K value                          __________________________________________________________________________    17   17    10       10      15       1.0     12.3                             18   18    10       10      16.5     0.93    9.0                              19   19    10       7.5     16.25    0.84    10.1                             20   20    20       10      35       1.0     11.3                             21   21    20       5       37.5     1.0     30.9                             __________________________________________________________________________

EXAMPLE 22

The above-indicated method is followed when a solution of 3.4 g (0.01mol) of sucrose in 2.25 g (0.015 mol) of triethylene glycol and 20 mg ofoxalic acid is prepared and heated to 130° C. At that temperature 3.9 g(0.0275 mol) of 1,4-butanediol divinyl ether are added, followed by 7.15g (0.055 mol) of ethyl vinyloxyacetate. The polyacetal obtained has a Kvalue of 15.6. Alkaline aftertreatment converts the polyacetal into itssodium salt form. The ratio of OH groups to vinyl ether groups was 1.0.

EXAMPLE 23

The above-indicated method is followed when a solution of 2 g (0.01 mol)of dextrose in 2.25 g (0.015 mol) of triethylene glycol and 20 mg ofoxalic acid is prepared and heated to 130° C. At that temperature amixture of 2.8 g (0.02 mol) of 1,4-butanediol divinyl ether and 5.2 g(0.04 mol) of ethyl vinyloxyacetate is added. The ratio of OH groups tovinyl ether groups in the starting materials is 1.03. The polyacetalobtained has a K value of 11. Alkaline aftertreatment converts thepolyacetal into its sodium salt form.

EXAMPLE 24

The above-indicated method is followed when a solution of 2.0 g (0.01mol) of dextrose in 2.25 g (0.015 mol) of triethylene glycol is preparedand admixed with 20 mg of oxalic acid. The reaction mixture is heated to130° C. and admixed at that temperature with a mixture of from 3.55 g(0.025 mol) of 1,4-butanediol divinyl ether and 3.9 g (0.03 mol) ofethyl vinyloxyacetate. The polyacetal obtained has a K value of 13.2.Alkaline aftertreatment with sodium hydroxide solution converts it intoits sodium salt form.

EXAMPLE 25

A mixture of 18.2 g (0.1 mol) of sorbitol, 0.15 g of oxalic acid and 13g (0.1 mol) of ethyl vinyloxyacetate is heated to 110° C. and stirred atthat temperature for 2 hours. In the course of this period, theinitially diphasic reaction mixture is converted into a homogeneousreaction product. Then 14.2 g (0.1 mol) of butanediol divinyl ether areadded, followed after 1 hours reaction time by 28 g (0.1 mol) ofoctadecyl vinyl ether, and the reaction mixture is then additionallystirred at 110° C. for 1 hour. Thereafter the vinyl ether group contentis 0.0003 mol. Alkaline aftertreatment gives the sodium salt. It hassurfactant properties.

USE TESTS Clay dispersion (CD)

The clay employed as a model of particulate soils is finely ground chinaclay SPS 151. 1 g of said clay is intensively dispersed for 10 minutesin 98 ml of water in a 100 ml cylinder in the presence of 1 ml of a 0.1%strength sodium salt solution of the polyelectrolyte. Immediately afterthe stirring has been stopped, a sample of 2.5 ml is removed from thecenter of the cylinder, diluted with 25 ml and measured in aturbidimeter. After this dispersion has stood for 30 and 60 minutes,further samples are taken and again measured in the turbidimeter. Theturbidity of the dispersion is reported in nephelometric turbidity units(NTUs). The less the dispersion settles on storage, the higher themeasured turbidity values and the more stable the dispersion. The secondphysical parameter determined is the dispersion constant τ, whichdescribes the time course of the sedimentation process. Since thesedimentation process approximates to a monoexponential time law, τindicates the time within which the turbidity decreases to 1/e-th of theoriginal level at t=0.

The higher the value of τ, the slower the rate of sedimentation in thedispersion.

                  TABLE 4                                                         ______________________________________                                                                   Dispersion                                                      NTUs after storage                                                                          constant τ                                     Example                                                                              Polyacetal No.                                                                            at once 30 min                                                                              60 min                                                                              (min)                                  ______________________________________                                        26      1          700     520   480   221                                    27      2          680     450   410   176                                    28     11          650     410   370   157                                           Comp. Ex. 1 600      37    33    41                                           without                                                                       polyacetal                                                             ______________________________________                                    

The above-described polyacetals can be used as viscosity reducers forsurfactants. Diluting concentrated, low-water or water-free surfactantformulations with water, as is customary in the sector of commerciallaundry or in the production of detergent formulations, frequently givesrise to a concentration range having a very high viscosity. Thisfrequently causes problems with the transport of the formulations inpipework, the metering by means of pumps and the rate of dissolution inthe wash liquor. A high viscosity necessitates a high level ofmechanical energy for processing the surfactants. Moreover, the highviscosity of the partially diluted surfactant means that the continuedprocess of dissolution of the surfactant will take longer. The increasein the viscosity of surfactants on dilution with water is observed inparticular in the case of nonionic surfactants, especially in the caseof polyalkoxylated compounds. If the surfactants are admixed with theabove-described polyacetals in amounts from 0.1 to 50, preferably from0.5 to 10, % by weight, the viscosity of such mixtures at dilution canbe distinctly reduced. The polyacetals to be used according to theinvention in detergents are preferably first dissolved or dispersed inthe concentrated surfactant. Thereafter the mixture is diluted withwater. The surfactant concentrate admixed with the polyacetals to beused according to the invention can also be introduced into an aqueouswash liquor. However, it is also possible to admix an alreadywater-admixed highly viscous dilute aqueous surfactant solution with thepolyacetals to be used according to the invention in order that theviscosity may be subsequently reduced.

EXAMPLES 29 TO 34

The polyacetals reported in Table 5 are tested in respect of theirsuitability for use as flow improvers for nonionic surfactants bypreparing a mixture of an anhydrous surfactant and the polyacetalsreported in Table 5. The surfactant used was an addition product of 7mol of ethylene oxide with 1 mol of a C₁₃ /C₁₅ -alcohol mixture. Theproportion of polyacetal in the mixture was 5%. Table 5 indicates theviscosities of the mixture of the abovementioned surfactant and thepolyacetals at different water contents. As the Table reveals, thepolyacetals described therein act as viscosity reducers for thewater-containing surfactant.

                  TABLE 5                                                         ______________________________________                                        Flow improvers for nonionic surfactants                                       Viscosity measurements as a function of surfactant content                                  Viscosity [mPas] of aqueous                                                   surfactant mixture having a                                                   nonionic surfactant content of                                  Example                                                                              Polyacetal No.                                                                             80%     60%    40%   20%                                  ______________________________________                                        29      5           92      6050   486   169                                  30      6           90      6210   591   172                                  31      7           106     3560   356   287                                  32     13           148     4120   412   250                                  33     14           121     3840   671   262                                  34     15           158     3670   651   281                                         Comp. Ex. No. 2                                                                            46000   25000  158000                                                                              1000                                        without polymer                                                        ______________________________________                                    

EXAMPLES 35 TO 37

Owing to their viscosity-reducing effect, the polymers to be usedaccording to the invention are important auxiliaries in the manufactureof phosphate-reduced and phosphate-free detergent and cleanerformulations. By using these auxiliaries it is possible to raise theslurry concentration in the Crutcher to at least 80%. This makes forbetter economics through better utilization of the spray drying towerand for an energy saving, since less water needs to be evaporated. Thehomogenizing and viscosity-reducing effect of the polymers to be usedaccording to the invention is illustrated in what follows by viscositymeasurements on detergent formulations. The measuring equipment used isa rheometer from Physika. The measuring system is a Z 3 DIN type. Thedetergent slurry used contains 80% by weight of detergent components and20% by weight of water. Viscosity-reducing additives used are thepolyacetals reported in Table 6, in an amount of 2% by weight, based onthe detergent formulation.

The detergent for the slurry has the following composition:

10% by weight of dodecylbenzenesulfonate in the form of the sodium salt

6% by weight of surfactant (addition product of 7 mol of ethylene oxidewith 1 mol of a C₁₃ /C₁₅ -alcohol mixture)

30% by weight of zeolite A

10% by weight of sodium carbonate

5% by weight of sodium metasilicate with 5H₂ O, and

39% by weight of sodium sulfate.

All the above-listed detergent components and each of the polyacetalslisted in Table 6 were stirred at 60° C. by means of a wing stirrer intowater so that a mixture consisting of

80 parts by weight of the above-described detergent components,

18 parts by weight of water, and

2 parts by weight of polyacetal

was formed. The viscosities of the slurries were measured at 20° C. anda shear rate of 45 seconds⁻¹. The results are reported in Table 6.

It is clear from the measurements reported in Table 6 that thepolyacetals have a homogenizing and viscosity-reducing effect on thedetergent slurries.

                  TABLE 6                                                         ______________________________________                                        Flow improvers for detergent slurries                                                             Viscosity                                                                              Visual appearance                                Example                                                                              Polyacetal   (mPas)   of slurry                                        ______________________________________                                        35     3            156      Low in viscosity,                                                             homogeneous                                      36     4            172      Low in viscosity,                                                             homogeneous                                      37     12           113      Low in viscosity,                                                             homogeneous                                             Comp. Ex. No. 3                                                                            28700    Very pasty, not                                         without polymer       homogeneous                                      ______________________________________                                    

We claim:
 1. Soluble polyacetals containing acetaldehyde acetal units,prepared by reacting(a) compounds containing at least 3 hydroxyl groups,(b) divinyl ethers containing terminal vinyl ether groups, or mixturesof such divinyl ethers and monovinyl ethers, and (c) dihydroxy compoundsand/or monohydroxy compounds,with acid catalysts which initiate thecationic polyaddition at temperatures of from -20° to 250° C., the ratioof the sum of the hydroxyl groups of compounds (a) and (c) to the sum ofthe vinyl ether groups of compounds (b) being from 0.1:1 to 10:1. 2.Soluble polyacetals containing acetaldehyde acetal units as claimed inclaim 1, wherein the ratio of the sum of the hydroxyl groups ofcompounds (a) and (c) to the sum of the vinyl ether groups of compounds(b) is from 0.5:1 to 5:1.
 3. A process for preparing water-solublepolyacetals containing acetaldehyde acetal units, which comprisesreacting(a) compounds containing at least 3 hydroxyl groups, (b) divinylethers containing terminal vinyl ether groups, or mixtures of suchdivinyl ethers and monovinyl ethers, and (c) dihydroxy compounds and/ormonohydroxy compounds andacid catalysts which initiate the cationicpolyaddition at temperatures of from -20° to 250° C. in such ratios thatthe ratio of the sum of the hydroxyl groups of compounds (a) and (c) tothe sum of the vinyl ether groups of compounds (b) being from 0.1:1 to10:1.
 4. A phosphate-reduced or phosphate free detergent comprisingsoluble polyacetals containing acetaldehyde acetal units, prepared byreacting(a) compounds containing at least 3 hydroxyl groups, (b) divinylethers containing terminal vinyl ether groups, or mixtures of suchdivinyl ethers and monovinyl ethers, and (c) dihydroxy compounds and/ormonohydroxy compounds, with acid catalysts which initiate the cationicpolyaddition at temperatures of from -20° to 250° C., the ratio of thesum of the hydroxyl groups of compounds (a) and (c) to the sum of thevinyl ether groups of compounds (b) being from 0.1:1 to 10:1. 5.Dispersants for finely divided minerals comprising soluble polyacetalscontaining acetaldehyde acetal units, prepared by reacting(a) compoundscontaining at least 3 hydroxyl groups, (b) divinyl ethers containingterminal vinyl ether groups, or mixtures of such divinyl ethers andmonovinyl ethers, and (c) dihydroxy compounds and/or monohydroxycompounds, with acid catalysts which initiate the cationic polyadditionat temperatures of from -20° to 250° C., the ratio of the sum thehydroxyl groups of compounds (a) and (c) to the sum of the vinyl ethergroups of compounds (b) being from 0.1:1 to 10:1.
 6. A viscosity reducerfor surfactants comprising soluble polyacetals containing acetaldehydeacetal units, prepared by reacting(a) compounds containing at least 3hydroxyl groups, (b) divinyl ethers containing terminal vinyl ethergroups, or mixtures of such divinyl ethers and monovinyl ethers, and (c)dihydroxy compounds and/or monohydroxy compounds, with acid catalystswhich initiate the cationic polyaddition at temperatures of from -20° to250° C., the ratio of the sum of the hydroxyl groups of compounds (a)and (c) to the sum of the vinyl ether groups of compounds (b) being from0.1:1 to 10:1.